Folding and positioning device for tier-seats

ABSTRACT

A folding and positioning device for tier-seats comprising several linked seats  1  in the same row with their pedestals  3 . At least one rotational leg  2  is fixed in the middle on the rotational shaft  7  on the upper front side inside the pedestal, its upper end fixed on the seat  1  and the lower end having a step. In the lower rear inside the pedestal is another rotational shaft  5 , on which is fixed a bracketing arm  6  in the position corresponding to the rotational leg  2 . When the seats are being erected to their upright position, the free end of the bracketing arm  6  abuts against the step at the lower part of the rotational leg  2 . Compared with conventional technologies, the present invention calls for very little force in order to erect or lay down the seats. Furthermore, the seats in the entire row are linked joint motion, thus greatly enhancing the efficiency.

FIELD OF THE INVENTION

[0001] The present invention relates to a folding and positioning devicefor tier-seats.

[0002] Folding tier-seats are commonly found on moveable spectatorstands in gymnasiums, conference halls and other places. For the sake ofsaving space, these moveable spectator stands are usually folded and putaway when in idle time, during which time all the tier-seats mounted inthe row should be lay down. And when these seats are put to use, therows of seats should be erected and fixated when the moveable spectatorstand is prepared. The conventional seats on moveable spectator standsare usually manually lifted and folded one by one or two by two. Theirstructure is characterized in that there is a pintle on the leg of theseat and the pintle is located within the arc-like sliding chute on thebracket of the seat (see FIG. 7). Therefore, when folding the seats, theentire weight of the seats should be overcome manually so as to make thepintle on the chair leg slide from the upper end of the arc-like slidingchute downwards to the concave at the lower end of the chair and belocked there. And when laying down the seats, the entire weight of theseats should also be overcome to pull the pintle of the chair leg out ofthe concave at the lower end of the arc-like sliding chute, and then theseats are supported to make the pintle of the chair leg slide from thelower end of the arc-like sliding chute to the upper end and put downthe chair. However, an ordinary spectator stand consists of at leastseveral hundred or even thousands of tier-seats; therefore, this mode ofchair-folding is labor-consuming and costs a lot of time and producesvery low efficiency. In addition, the use of sliding chute lockingstructure can hardly remove the moving clearance, thus resulting ininstability and sway of the seats.

[0003] The aim of the present invention is to provide a folding andpositioning device for tier-seats capable of folding in a row of seatsin linkage based on current technologies.

[0004] Another objective of the present invention is to provide afolding and positioning device for tier-seats capable of achieving firmfixation.

[0005] A further objective of the present invention is to provide afolding and positioning device for tier-seats which dispenses with theneed to overcome the entire weight of the seats when laying them down.

[0006] A further objective of the present invention is to provide afolding and positioning device for tier-seats dispensing with the needto overcome the entire weight of the seats when unfolding them.

SUMMARY OF THE INVENTION

[0007] The aims of the present invention are realized thus: the foldingand positioning device for tier-seats comprising several seats withtheir pedestals mounted in the same row, characterizing in that theseats are linked up as a whole and there is at least one rotational leg,which is fixed in the middle on the rotating shaft located at the frontupper part of the interior of the pedestal, the upper end of therotational leg is fixed on the seats and a step is provided on its lowerend, another rotating shaft is provided at the lower rear part in thepedestal, on which a bracketing arm is fixed in the positioncorresponding to the rotational leg . When the seats are in an unfoldedand positioned state, the free end of the bracketing arm abuts againstthe step at the lower end of the rotational leg.

[0008] An adjusting bolt is provided at the upper end of the pedestaland when the seats are unfolded and positioned, the outer extending endof the bolt abuts against the back of the rotational leg.

[0009] A gravity balance torsion spring can preferably be mounted on therotational shaft in the middle of the rotational leg, one end of thetorsion spring is secured to the rotational leg, and the other end issecured to the fixed bracket in the corresponding position on thepedestal.

[0010] The seats can be linked up together by the transverse tube thatruns through the middle part of the legs of the seats and the transversetube can also run through the upper end of the rotational leg.

[0011] Compared with conventional technology, the present invention hasseveral advantages in use. When laying down the tier-seats, we need onlyto make the axis of the bracketing arm rotate manually or electricallyso as to make the bracketing arm rotate downwards and move away from thesteps at the end of the rotational leg. Then we need only to push orpull gently the seats so that the linked seats fall down under their owngravitational force. When erecting the seats, we need only to overcomepart of the gravitation of the seats manually because of the returnedforce of the gravity balance torsion spring. When the seats are restoredto their positions, the bracketing arm then extends beneath the stepsunder the lower end of the rotational leg and thus achieve fixation,making possible the synchronic folding and erecting of the entire row ofseats, which is a tremendous enhancement of efficiency. Furthermore, thezero clearance of the adjusting bolt completely eliminates the shakingof the seats.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 shows the structure of the present invention (partialsectional view).

[0013]FIG. 2 is a partial enlarged view of FIG. 1.

[0014]FIG. 3 is a top view of FIG. 1 (partial sectional view).

[0015]FIG. 4 is an enlarged sectional view taken along line A-A of FIG.3 (FIG. 4a, 4 b and 4 c showing the three different states of the seatsbefore and after the stepping arm is pressed down when the seats arebeing laid down and when the seats are being erected.)

[0016]FIG. 5 is an enlarged sectional view taken along line B-B of FIG.4 (FIG. 5a and 5 b showing the two different states of the seats whenthey are being laid down and when they are erected in position.)

[0017]FIG. 6 is an exploded perspective view of the stepping arm 8, thetransmission bushing 52, the rotational axis 5 and the footplate 81.

[0018]FIG. 7 is a structural representation of the conventional foldingand positioning device for seats.

DETAILED DESCRIPTION OF THE INVENTION

[0019] Below is a detailed description of an embodiment of the presentinvention with reference to the drawings.

[0020] FIGS. 1 to 6 show an embodiment of the manually-folding seats,the folding and positioning device for tier-seats comprises severalseats 1 and their pedestals 3 arranged in the same row. Each tier-seat 1can be linked up as a whole through a transverse tube 12 that runsthrough the seat leg 11 in the middle; the cross section of thetransverse tube 12 can be in any shape but circular and it can not berotated relative to the seats. The cross section of the transverse tube12 in the present invention takes the form of a rectangle. Therefore,whenever one of the tier-seats in the row is being restored to positionor laid down, the transverse tube 12 then revolves simultaneously,causing the synchronic folding or erecting of the other seats in therow.

[0021] At least one rotational leg 2 should be installed in a properposition on the transverse tube 12. The upper end of the rotational leg2 runs through the transverse tube 12. The rotational leg 2 is fixed onthe rotational shaft 7 on the upper front side of the interior of thepedestal 3 (the two ends of the rotational shaft 7 are fixed on thefixed bracket 31 inside the pedestal 3 through bearings respectively).On the lower side there is a step, where the upper end of the rotationalleg 2 penetrates the transverse tube 12 so as to join the upper end ofthe rotational leg 2 with seat 1. This can also be achieved throughalternative means. For example, it can also be fixed by a bolt on thechair leg 12 directly or by welding.

[0022] There is a gravity balance torsion spring 71 encasing therotational shaft 7 in the middle of the rational leg. In the embodimentof the present invention, there are two symmetrical springs on eachseat. As shown in FIG. 3, one end of the torsion spring 71 is fixed onthe rotational leg 2, and the other end is fixed on the fixed bracket31.

[0023] There is an adjusting bolt 4 set on the upper part of thepedestal 3. When the seat 1 is being erected to its position, the bolt 4stretches out to prop the back of the rotational leg 2, as shown in FIG.1.

[0024] There is a long rotational shaft 5 set on the lower in the rearof the pedestal 3 and a bracketing arm 6 is installed in the positionthat corresponds to the rotational leg 2 on the rotational shaft 5. Oneend of the bracketing arm 5 encases the rotational shaft 5 circularlyand is integrated with the rotational shaft by the bolt. There is atleast one torsion spring 51 on the rotational shaft 5, which is fixed tothe shaft 5 at one end and to one of the fixed brackets 31 inside thepedestal 3 at the other end. If the torsion spring 51 is installedproperly, the torsion moment produced by the torsion spring 51, when theseat is in a laid down position, can restore the free end of thebracketing arm 6 to its position which points a little upwards. For thesake of easy installation, a better design is to set torsion moment ofthe torsion spring 51 sufficiently high and fix an extending restrictingarm 9 in another proper position on the rotational shaft 5, with theadjoining fixed bracket 32 having a protrusion over the restricting arm.As shown in FIG. 5b, when the seat 1 is laid down, the free end of thebracketing arm 6 moves upwards with the shaft 5 under the force of thetorsion spring 51 until the restricting arm 9 is stopped by the cam ofthe fixed bracket 32 that is adjacent to the restricting arm, as shownin FIG. 5a.

[0025] At least one stepping arm 8 is joined on the rotational shaft 5,the circular bushing on the end of the stepping arm 8 encases therotational shaft 5 and can rotate relative to the rotational shaft 5.The circular bushing has an arc-shaped nick and the side cam of thetransmission bushing 52 which sheathes the rotational shaft 5 and isfixed by the bolt is just located in the arc-shaped nick and keeps aclearance in it. As shown in FIG. 4 and FIG. 6, 53 represents arestricting bushing, the free end of the stepping arm 8 is hinged on afootplate 81, which covers a gap in the pedestal 3. A weight block 82can be set at the lower part on the inner side of the footplate 81.

[0026] The seat 1 can be laid down by stepping on the footplate 81 andthe stepping arm 8, making the stepping arm 8 revolve downwards, thussetting the transmission bushing 52 in motion and causing the rotationalshaft 5 to revolve, as is shown in FIG. 4b. The bracketing arm 6 fixedon the rotational shaft 5 then revolves downwards and moves away fromthe steps at the end of the rotational leg 2, and the entire row ofseats will fall down automatically under their own gravitational forceif we give any one of the seats a gentle push or pull. The rotationalshaft 5 revolves reversely under the force of the torsion spring 51until the restricting arm 9 on the rotational shaft 5 is stopped by thecam of the adjacent fixed bracket 32. At this time, the bracketing arm 9reverts to its horizontal position with a slight upward orientation andthe transmission bushing 52 drives the stepping arm 8 to revolve in theopposite direction and restore to its original state.

[0027] When restoring the seats 1 to their original erectile position,the only thing needed to do is to overcome manually part of thegravitational force of the seats because of the return action of thegravity balance torsion spring 71. When the seats nearly completes itsfull restoration, the lower part of the rotational leg 2 first pushesthe bracketing arm 6 downwards. At this moment, the transmission bushing52 revolves simultaneously. However, because of the clearance retainedon the arc-shaped nick of the circular bushing of the stepping arm 8,the cam of the transmission bushing 52 revolves separately in thearc-shaped nick of the circular bushing of the stepping arm 8 withoutcausing the synchronic revolution of the stepping arm 8, as shown inFIG. 4c. When the seats reverts to its position completely, thebracketing arm 6 returns and extends beneath the steps at the lower partof the rotational leg 2, thus fixing the seats in position.

[0028] The transverse tube 12 in the above embodiment is only one meansof linking up the seats. The seats can be joined together by othercurrent means so as to make them move simultaneously when being foldedor erected.

[0029] The laying down of the seats in the above embodiment is realizedby stepping on the plate. According to the present invention, therotational shaft 5 can also be motor-driven, and the structure of thedriving motor is omitted here.

What is claimed is:
 1. A folding and positioning device for tier-seatscomprising several seats (1) with their pedestals (3) mounted in thesame row, characterizing in that the respective seat (1) are linked upas a whole and there is at least one rotational leg (2), which is fixedin the middle on a rotating shaft (7) located at the front upper part ofthe interior of the pedestal, the upper end of the rotational leg isfixed on the seat (1) and a step is provided on its lower end, anotherrotating shaft (5) is provided at the lower rear part in the pedestal,on which a bracketing arm (6) is fixed in the position corresponding tothe rotational leg (2), when the seats are in an unfolded and positionedstate, the free end of the bracketing arm (6) abuts against the step atthe lower end of the rotational leg (2).
 2. A folding and positioningdevice for tier-seats according to claim 1 , characterizing in that anadjusting bolt (4) is provided at the upper end of said pedestal (3) andwhen the seats are unfolded and positioned, the outer extending end ofthe bolt (4) just abuts against the back of the rotational leg (2).
 3. Afolding and positioning device for tier-seats according to claim 1 ,characterizing in that a gravity balance torsion spring (71) is mountedon the rotational shaft (7) in the middle of said rotational leg (2),one end of the torsion spring (71) is secured to the rotational leg (2),and the other end is secured to the fixed bracket (31) in thecorresponding position on the pedestal (3).
 4. A folding and positioningdevice for tier-seats according to claim 1 or 2 or 3, characterizing inthat the respective seat (1) is linked up together by a transverse tube(12) that runs through the middle part of a legs (11) of the seat.
 5. Afolding and positioning device for tier-seats according to claim 4 ,characterizing in that the upper end of said rotational leg (2)penetrates said transverse tube (12).
 6. A folding and positioningdevice for tier-seats according to claim 1 or 2 or 3, characterizing inthat on the rotational shaft (5) there is at least one torsion spring(51) which maintains the free end of the bracketing arm (6) in itshorizontal or vertical positions, said torsion spring (51) is fixed tothe rotational shaft (5) at one end and to one of the fixed brackets(31) inside the pedestal 3 at the other end.
 7. A folding andpositioning device for tier-seats according to claim 5 , characterizingin that on the rotational shaft (5) there is at least one torsion spring(51) which maintains the free end of the bracketing arm (6) in itshorizontal or vertical positions, said torsion spring (51) is fixed tothe rotational shaft (5) at one end and to one of the fixed brackets(31) inside the pedestal 3 at the other end.
 8. A folding andpositioning device for tier-seats according to claim 1 or 2 or 3,characterizing in that at least one stepping arm (8) is connected tosaid rotational shaft (5).
 9. A folding and positioning device fortier-seats according to claim 8 , characterizing in that said steppingarm (8) has a circular bushing sheathing the rotational shaft (5), saidcircular bushing having an arc-shaped nick, a side cam of a transmissionbushing (52) which sheathes the rotational shaft (5) and is fixedthereupon is located just in the arc-shaped nick and keeps a clearancein it.
 10. A folding and positioning device for tier-seats according toclaim 9 , characterizing in that the free end of the stepping arm (8) ishinged on a footplate (81), which covers a gap in the pedestal (3).